Air pollution measured

Press, Volume CX, Issue 32431, 19 October 1970, Page 17

Air pollution measured

WASHINGTON, October 17. Scientists today reported that the air over the North Atlantic Ocean was twice as dirty as it was in the early 1900 s. This is disturbing news for those weather experts who fear that air pollution, if it continues unchecked, will seriously affect the climate and perhaps bring on a new ice age. Air-pollution over the Indian Ocean off South-East Asia also appears to have doubled in this century, but the South Pacific atmosphere remains as clean as it was. The increase of air contamination over the North Atlantic attributed to manmade pollutants, was reported by scientists of the National Oceanic and Atmospheric Agency (N.0.A.A,). They arrived at their conclusions after comparing data on atmospheric electrical conductivity obtained early in the century with similar data

gathered on a recent global research cruise. Dust-like “particulates” (aerosols) suspended in the air reduce its conductivity. So conductivity measurements are also a measure of air pollution. And air pollution reduces the amount of sunlight reaching the earth’s surface, thus influencing weather. The data used for comparison purposes were collected between 1909 and 1929 by Carnegie Institution scientists aboard the sailing ships Carnegie and Galilee, and in 1967 by N.O.A.A. scientists aboard the modem research ship Oceanographer. The possibly serious implications of increasing air pollution were reported by a meteorologist, Mr William Cobb, of N.O.A.A.’s atmospheric physics and chemistry laboratory (A.P.C.L.), in Boulder, Colorado. One of A.P.C.L.’s jobs is to watch out for unintended effects of man’s activities on weather and climate. Said Mr Cobb: “We know we are changing the atmos-

phere. We must know how and at what ,rate we are changing it.” So far nature had always been able to take care of her own pollution, Mr Cobb said. Even such cataclysmic events as the eruption of Krakatoa (1883 in Indonesia) have upset the aerosol balance for not more than a few years. “Another ice age,” said Mr Cobb, “is possible.” Another A.P.C.L. scientist at Boulder, Dr Earl Barrett, has calculated that addition of 50 million tons of pollutant particles to the atmosphere, might lower the earth’s average surface temperature from its present level of 60 degrees to about 40 degrees. "Most forms of plant life could not survive in such an icy world,” Dr Barrett said. The 50 million additional tons of pollutants which “could start us irrevocably towards the next ice age,” N.O.A.A. pointed out, “is only 10 to 20 times greater than the present background of particulate matter in the atmosphere.”